Display Device, Display Control Method, and Display System

1. A display device comprising: a communication unit to which image data is inputted from an image supply device; a detection unit which detects a position of an indicator on a display surface and generates indicator information, which is information about the detected position of the indicator on the display surface; a setting unit which sets a mode for processing of the indicator information to a first mode or a second mode; a drawing unit which draws a second image generated on the basis of the indicator information and superimposes the second image on a first image generated on the basis of the inputted image data; a selection unit which outputs, to the drawing unit, the indicator information generated based on the position of the indicator detected while the first mode is set, and which outputs, to the image supply device, the indicator information generated based on the position of the indicator detected while the second mode is set; and a drawing control unit which erases the second image if a switching from the first mode to the second mode is carried out.

2. The display device according to claim 1 , wherein the drawing control unit executes the erasure of the second image if it is detected that the first image is updated, after the switching is carried out.

3. The display device according to claim 1 , wherein the drawing control unit executes the erasure of the second image if a predetermined period passes without having the first image updated, after the switching is carried out.

4. The display device according to claim 1 , further comprising a storage unit which stores the second image, wherein the drawing control unit stores the second image in the storage unit before executing the erasure of the second image.

5. The display device according to claim 1 , wherein the indicator information comprises coordinates of the detected position of the indicator on the display surface.

6. The display device according to claim 1 , wherein the second mode comprises a mode in which the indicator information is processed other than by drawing an image generated on the basis of the indicator information.

7. The display device according to claim 1 , wherein the second mode comprises a mode in which the indicator information is configured to control an operation by the image supply device.

8. The display device according to claim 1 , wherein the second mode comprises a mode in which the indicator information is configured to change the first image.

9. The display device according to claim 1 , wherein the image supply device is a computer.

10. The display device according to claim 9 , wherein in the second mode, an application executed by the computer performs a predefined operation based on the indicator information received from the display device.

11. A display control method comprising: inputting image data from an image supply device; detecting a position of an indicator on a display surface and generating indicator information, which is information about the detected position of the indicator on the display surface; setting a mode for processing of the indicator information to a first mode or a second mode; causing a drawing unit to draw a second image generated on the basis of the indicator information and superimpose the second image on a first image generated on the basis of the inputted image data; outputting, to the drawing unit, the indicator information generated based on the position of the indicator detected while the first mode is set, and outputting, to the image supply device, the indicator information generated based on the position of the indicator detected while the second mode is set; and erasing the second image if a switching from the first mode to the second mode is carried out.

12. A display system comprising: an image supply unit; a communication unit to which image data is inputted from the image supply unit; a detection unit which detects a position of an indicator on a display surface and generates indicator information, which is information about the detected position of the indicator on the display surface; a setting unit which sets a mode for processing of the indicator information to a first mode or a second mode; a drawing unit which draws a second image generated on the basis of the indicator information and superimposes the second image on a first image generated on the basis of the inputted image data; a selection unit which outputs, to the drawing unit, the indicator information generated based on the position of the indicator detected while the first mode is set, and which outputs, to the image supply unit, the indicator information generated based on the position of the indicator detected while the second mode is set; and a drawing control unit which erases the second image if a switching from the first mode to the second mode is carried out.

13. A display device comprising: a communication unit to which image data is inputted from an image supply device; a detection unit which detects a position of an indicator on a display surface and generates indicator information, which is information about the detected position of the indicator on the display surface; a setting unit which sets a mode for processing of the indicator information to a first mode or a second mode; a drawing unit which draws an image generated on the basis of the indicator information; a selection unit which outputs, to the drawing unit, the indicator information generated based on the position of the indicator detected while the first mode is set, and which outputs, to the image supply device, the indicator information generated based on the position of the indicator detected while the second mode is set; and a drawing control unit which erases the image if a switching from the first mode to the second mode is carried out.